Watson- Crick base pairing

Background

In 1953, James D Watson and Francis Crick discovered the structure of DNA using X ray Crystallography. They worked out that DNA was a double helix using Rosalind Franklin's X ray diffraction pattern.[1] At first, it was thought that DNA was made up of many chemicals, which proved too difficult to analyse, but the researchers persisitence led to the discovery of complementary base pairing.